Comparative in vitro activities of selected antimicrobial agents against Edwardsiella tarda

Abstract

MICs of 14 antimicrobial agents for 29 strains of Edwardsiella tarda were determined by an agar dilution method. Of the agents tested, ciprofloxacin, enoxacin, and norfloxacin were the most active on a weight basis. All strains were also susceptible to clinically achievable concentrations of ampicillin, chloramphenicol, tetracycline, trimethoprim, sulfamethoxazole, trimethoprim plus sulfamethoxazole, cefotaxime, and gentamicin. Ninety percent of the strains demonstrated high-level resistance to polymyxin B and colistin.

Mechanisms of intrinsic resistance to antimicrobial peptides of Edwardsiella ictaluri and its influence on fish gut inflammation and virulence

“…This contrasts to the situation in Salmonella and Yersinia where the ugd gene does not overlap with other adjacent genes and has its own promoter under control of PhoP (Winfield et al, 2005). The fact that the E. ictaluri ugd gene is controlled by a jump-start promoter correlates with the intrinsic constitutive resistance to CAMPs described in the early literature (Muyembe et al, 1973;Reinhardt et al, 1985;Stock & Wiedemann, 2001) and is coincident with our data (Table 2). However, the subtle regulation observed in E. ictaluri ugd and arnT genes (Fig.…”

“…Since its first description, Edwardsiella has been characterized by a constitutive resistance to CAMPs (Muyembe et al, 1973;Reinhardt et al, 1985;Stock & Wiedemann, 2001) in contrast to the regulated resistance described in Salmonella and Yesinia (Aguirre et al, 2000;Gunn et al, 1996;Kato et al, 2003;Kox et al, 2000;Winfield et al, 2005;Wösten & Groisman, 1999). As previously mentioned, in Salmonella resistance to CAMPs is induced after exposure to sublethal concentrations of CAMPs or by inducing the activation of PhoP and RscB response regulators that upregulate the expression of the ugd gene (Gunn et al, 1996;Kox et al, 2000).…”

“…Edwardsiella species are particularly resistant to the CAMP polymyxin B and colistin (also called polymyxin E) (Muyembe et al, 1973;Reinhardt et al, 1985;Stock & Wiedemann, 2001). Several components of the lipopolysaccharide (LPS) are important for CAMP resistance.…”

“…Edwardsiella bacteria differ strongly in their biochemical and physiological features, natural habitats, and pathogenic properties. High intrinsic resistance to cationic antimicrobial peptides (CAMPs) is one of the particular properties of the genus Edwardsiella (Muyembe et al, 1973;Reinhardt et al, 1985;Stock & Wiedemann, 2001). …”

In vitro combination effects of natural substances and antimicrobials against Edwardsiella tarda and Streptococcus iniae

“…Kang et al (2008)의 보고에서도 E. tarda에 대한 flumequine의 MIC가 0.0781 μg/ml 로 나타났으며, nalidixic acid의 MIC가 2 μg/ml로 보고된바 있다 (Reinhardt et al, 1985). Barry et al (1984) Thy-thymol, Car-carvacrol, Eug-eugenol, Cin-cinnamaldehyde, Que-quercetin, Amp-ampicillin, Amo-amoxicillin, Cepcephalexin, Tet-tetracycline, Oxy-oxytetracycline, Dox-doxytetrcycline, Neo-neomycin, Str-streptomycin, ry-erythromycin, Jos-josamycin, Spi-spiramycin, Oxo-oxolinic acid, Flu-flumequine, Nal-nalidixic acid, Thi-thiamphenicol, Chl-chloramphenicol, Smt-sulfamethazine, Sfm-sulfamonomethoxine, Sfd-sulfadimethoxine, Sfx-sulfisoxazole (Lambert et al, 2001), LPS의 방출 과 ATP로 세포질 막의 투과율을 증가시켜 그람음 성균의 외막을 분해하여 항균작용을 나타낸다고 보고되었으며 (Burt, 2004), 항생제와 병용하여 사 용하면 세포막의 투과율을 증강시켜 내성균에 대 한 상승작용이 나타난다고 보고되어진바 있다 (Hemaiswarya et al, 2008 …”